1. Field of the Invention
The present invention relates generally to a telephone, and more particularly, to a mobile telephone.
2. Background of the Related Art
Referring to FIG. 1, a related art mobile terminal or subscriber unit includes a mobile station modem (MSM) 10, and user functions such as a vibration motor 11, back-light circuitry 12, audio alert circuitry 13, and LED display 14. The operations of the MSM 10 include controlling an audio alert 13 such as a buzzer or ringer, the vibration motor 11, and the back-light circuitry 12 and/or the LED display 14 user functions. The MSM 10 controls the user functions by detecting an input from a key button on the keypad, the opening of the telephone's flip, or reception of an incoming call.
A user can select desired user preferences for controlling the operation of the user functions through a menu. For example, the user can select the user preferences so that the back-light is turned on when the flip is opened or when the phone rings. The user can also set the user preferences so that when the phone rings, the MSM 10 drives the vibration motor 11 or audio alert 13 according to the user's menu settings, and then activates the back-light 12. When any user function is activated, power is supplied to the circuitry driving the user function from the battery.
Based on the type of mobile terminal, the user may set the user preferences to enhance the convenience of using the terminal by enabling or disabling certain user functions. For example, the user may alternatively set the user preferences to turn on the back-light by activating the back-light section 12 with the MSM. In the case of a bar type terminal, the back-light can be set to turn on when the phone rings or when the user presses a key button to key-in a telephone number. In case of a flip type or folder type terminal, the back-light can be set to activate when the phone rings or the user opens the flip or cover to place a call.
The related art mobile terminal has various problems. For example, user functions that are not essential to telephone call transmission or reception are performed whenever its user preference settings are satisfied. Thus, selected user functions will continue to be activated irrespective of the remaining capacity of the battery.
Specifically, in the case of the bar type mobile-telephone, the back-light, vibration motor, and audio alert may be set to activate whenever a key button is pressed or the phone rings. These features draw substantial current from the battery. In the case of the flip type or folder type mobile telephone, the back-light may activate whenever the user opens the flip or cover and the telephone is in standby mode and presents similar power consumption problems.
Moreover, other additional functions such as the vibration motor, LED, etc., are always activated irrespective of the remaining capacity of the battery, whenever the condition for the user preference is satisfied. Thus, even when the battery power is low, the same amount of current is consumed as when the battery power is high. Accordingly, when the battery power is low, the continued operation of the user functions depletes the already small amount of power remaining in the battery, and unnecessarily limits the remaining time during which the mobile telephone can transmit or receive a telephone call.